It is proposed to study the chemical and physicochemical properties of the Beta-adrenergic receptor from turkey erythrocytes, skeletal myoblasts grown in culture and HeLa cells grown in culture. Attempts will be made to purify the Beta-receptor subunit(s) using radioactivity labelled affinity labels. Attempts will also be made to purify the Beta-receptor in its oligomeric state from Beta-receptor enriched turkey erythrocyte membranes. If successful attempts will be made to reconstitute a functional hormone responsive adenylate cyclase from the three components of the systems: the receptor, the guanyl nucleotide binding proteins and the cyclase catalytic unit.. Attempts will also be made to determine the stoichiometry between these three components. A biotin containing propranolol analogue will be prepared and used to study the ultrastructural distribution of Beta-receptors on cell surfaces, using the avidin-ferritin conjugate as the electron-microscopical probe. In parallel fluorescence Beta-blockers will be used to explore receptor distribution and its mobility on cell surfaces. Kinetic experiments will be conducted in order to explore in detail the mode of coupling between the receptor and the enzyme. Attempts will be made to correlate the kinetic data with structural information on the receptor and its dynamic behavior within the intact membrane.